Sintered hard metallic alloy



Patented Feb. 19, 1935 UNITED STATES PATENT OFFICE This invention relates to sintered hard metallic alloys for use in the manufactureof implements and tools, the alloys being of the kind which consist of two components, one being a carbide 5 or carbide mixture of metals diflicult to melt and the other being a metal of substantially lower melting point such as iron, cobalt or nickel. Hitherto in practice tungsten carbide has principally been used as the component of higher melting point since the hard metallic alloys made with the use of tungsten carbide show the most satisfactory properties with respect to hardness, strength and toughness and farexceed in this respect the hard metallic alloys made with the use of other carbides of metals difiicult to melt such, for example, as molybdenum carbide, titanium Karl Schriiter, Berlin-Lichtenberg, and Hans Wolff, Berlin, Germany, assignors to Fried.

Krupp Aktiengesellschatt, Essen-on-the-Ruhr,

Germany No Drawing. Application August 4, 1931, Serial V No. 555,072. In Germany August 14, 1930 9 Claims.

carbide and silicon carbide.

Researches have now shown that with such hard metallic alloys the requirements of great hardness and very considerable strength and toughness are also fulfilled if the carbide component of the alloy consists of a mixture of certain other carbides of metals of very high melting. According to the invention this carbide component consists of a mixture of vanadium carbide with niobium carbide or with tantalum carbide, or with both niobium carbide and tantalum carbide. It has been found by extensive researches that with a hard metallic alloy of such a composition the great hardness is produced by the niobium or tantalum carbide present while the great toughness is produced by the vanadium'carbide which is likewise present and which serves at the same time to remove to a very large extent the brittleness which would be introduced by the niobium or tantalum carbide.

An alloy sintered at about 2000 C. and consisting of approximately equal parts of vanadium carbide and niobium carbide with an addition of from 225% to 5% of iron or cobalt has been found to be particularly suitable. In accordance as greater toughness or hardness of the finished product is desired the amount of the vanadium carbide or of the niobium or tantalum carbide may be made the greater in the carbide mixture. The amount of the more easily melting metal added may be increased if desired to about 25% of the whole alloy. The sintering of the alloy may take place subsequently to the pressing of the powder mixture which is used as the starting material or simultaneously with the pressing.

What we claim and desire to secure by Letters point.

Patent is:---

group.

4. A sintered hard metallic alloy composed of a mixture of vanadium carbide with one'or both of the carbides of tantalum and niobium, and 2.5%

to 5% of cobalt.

5. A sintered hard metallic alloy composed of a mixture of vanadium carbide with one or both of the carbides of tantalum and niobium, and about 2.5 to 25% of a metal of the iron group, the proportion of vanadium carbide to the carbides of tantalum and/or niobium being adjusted so that there is a preponderance of the former or the latter, depending upon whether greater toughness or hardness is desired in the alloy.

6. A sintered hard metallic alloy composed of a mixture of approximately equal proportions of vanadium carbide and one or both of the carbides of tantalum and niobium, and 2.5% to 25% of one or more metals of the iron group.

'7. A sintered hard metallic alloy composed of a mixture of approximatelyequal proportions of vanadium carbide and one or both of the carbides of tantalum and niobium, and 2.5% to 5% of cobalt.

8. A sintered hard metallic alloy composed of a mixture of approximately equal proportions of vanadium carbide and one or both of the carbides of tantalum and niobium, and 2.5% to 5% of iron.

9. A sintered hard metallic alloy composed of a mixture of vanadium carbide with one or both of the carbides of tantalum and niobium, and one or more metals of the iron group in proportion not over 25% of the whole, the proportion of vanadium carbide to the carbides of tantalum and/or niobium being adjusted so that there is apreponderance of the former or the latter, depending upon whether greater toughness or hardness is desired in the alloy.

KARL scrmo'rna.

HANS wom r'. 

